Conventional circuit interrupting devices, such as circuit breakers, sectionalizers, and reclosers, provide protection for power distribution systems and the various apparatus on those power distribution systems by isolating a faulted section from the main part of the system. A fault current in the system can occur under various conditions, including lightning, an animal or tree shorting the power lines, or different power lines contacting each other.
Conventional circuit interrupting devices sense a fault and interrupt the current path. Conventional reclosers also re-close the current path and monitor continued fault conditions, thereby re-energizing the utility line upon termination of the fault. This provides maximum continuity of electrical service. If a fault is permanent, the recloser remains open after a certain pre-set number of reclosing operations.
Conventional circuit interrupters typically have opposing contacts. The opposing contacts move from an open position where the contacts are separated and no current passes between them to a closed position where the contacts abut one another, allowing current to pass between them. The contacts are usually sealed into a vacuum bottle to minimize the arcing that occurs when the contacts are opened and closed. Arcing is undesirable because it causes erosion of the contacts. Arcing can also weld the opposing contacts together, effectively preventing operation of the circuit interrupter.
Examples of conventional circuit interrupting devices include U.S. Pat. No. 6,242,708 to Marchand et al.; U.S. Pat. No. 5,663,712 to Kamp; U.S. Pat. No. 5,175,403 to Hamm et al.; U.S. Pat. No. 5,103,364 to Kamp; U.S. Pat. No. 5,099,382 to Eppinger; U.S. Pat. No. 4,568,804 to Luehring and U.S. Pat. No. 4,323,871 to Kamp et al. The subject matter of each of these patents is incorporated herein by reference in its entirety.